US2023340678A1PendingUtilityA1

Super electrochemical corrosion-resistant bilayer passive film structure and stainless steel suitable for water electrolysis industry

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Assignee: UNIV HONG KONGPriority: Apr 21, 2022Filed: Apr 21, 2023Published: Oct 26, 2023
Est. expiryApr 21, 2042(~15.7 yrs left)· nominal 20-yr term from priority
Inventors:Mingxin HuangKaiping Yu
C22C 38/04C22C 38/58C25B 11/061C22C 38/02C25B 1/04C25B 11/077C25B 11/052C25D 11/34C22C 30/00C22C 38/34C22C 38/06C22C 38/50C22C 38/46
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Claims

Abstract

A bilayer passive film structure of a substrate, comprising an inner layer comprising an oxide of a first element, and an outer layer comprising an oxide of a second element, wherein the passivation potential of the first element is lower than the passivation potential of the second element, and the passivation potential of the second element is lower than the transpassivation potential of the first element. Also a method of forming the above bilayer passive film structure of a substrate, comprising: treating a surface of the substrate containing Cr and Mn. Further a stainless steel comprises, in percentage by weight, 15%<Cr<22%, 13%<Mn<23%, 12%<Ni<23%, and 0.5%<Si<4%, wherein Si can be replaced with an equal amount of Al, Ti or V.

Claims

exact text as granted — not AI-modified
1 . A bilayer passive film structure of a substrate, comprising an inner layer comprising an oxide of a first element, and an outer layer comprising an oxide of a second element, wherein the passivation potential of the first element is lower than the passivation potential of the second element, and the passivation potential of the second element is lower than the transpassivation potential of the first element. 
     
     
         2 . The bilayer passive film structure according to  claim 1 , wherein the passivation potential of the second element is not greater than 1000 mV. 
     
     
         3 . The bilayer passive film structure according to  claim 2 , wherein the passivation potential of the second element is 700 mV to 800 mV. 
     
     
         4 . The bilayer passive film structure according to  claim 1 , wherein the second element is Mn. 
     
     
         5 . The bilayer passive film structure according to  claim 1 , wherein the first element is Cr. 
     
     
         6 . The bilayer passive film structure according to  claim 1 , wherein the substrate comprises stainless steel. 
     
     
         7 . The bilayer passive film structure according to  claim 1 , wherein the substrate comprises austenitic stainless steel. 
     
     
         8 . The bilayer passive film structure according to  claim 1 , wherein the structure has no pitting at <1000 mV in an acidic or neutral environment. 
     
     
         9 . The bilayer passive film structure according to  claim 8 , wherein the structure has no pitting at <1150 mV in an acidic or neutral environment. 
     
     
         10 . A method of forming the bilayer passive film structure of a substrate according to  claim 1 , comprising: treating a surface of the substrate containing Cr and Mn. 
     
     
         11 . The method according to  claim 10 , wherein the substrate comprises, in percentage by weight, 15%<Cr<22%, 13%<Mn<23%, 12%<Ni<23%, and 0.5%<Si<4%, wherein Si can be replaced with an equal amount of Al, Ti or V. 
     
     
         12 . The method according to  claim 10 , wherein the substrate comprises, in percentage by weight, 15%<Cr<30%, 10%<Mn<30%, and 0.5%<Si<4%, wherein Si can be replaced with an equal amount of Al, Ti or V. 
     
     
         13 . A stainless steel, comprising, in percentage by weight, 15%<Cr<22%, 13%<Mn<23%, 12%<Ni<23%, and 0.5%<Si<4%, wherein Si can be replaced with an equal amount of Al, Ti and/or V. 
     
     
         14 . The stainless steel according to  claim 13 , further comprising a rare earth element. 
     
     
         15 . The stainless steel according to  claim 13 , comprising, in percentage by weight, 18%<Cr<20%, 18%<Mn<20%, 15%<Ni<20%, and 1%<Si<2%. 
     
     
         16 . The stainless steel according to  claim 13 , comprising, in percentage by weight, 18%<Cr<20%, 18%<Mn<20%, 15%<Ni<20%, 1%<Si <2%, and a remainder of Fe and inevitable impurities. 
     
     
         17 . A stainless steel, comprising, in percentage by weight, 15%<Cr<30%, 10%<Mn<30%, and 0.5%<Si<4%, wherein Si can be replaced with an equal amount of Al, Ti or V. 
     
     
         18 . The stainless steel according to  claim 17 , comprising, in percentage by weight, 15%<Cr<30%, 10%<Mn<30%, 0.5%<Si<4%, and a remainder of Fe and inevitable impurities. 
     
     
         19 . The stainless steel according to  claim 17 , comprising, in percentage by weight, 22%<Cr<25%, 24%<Mn<26%, and 1.5%<Si<2.5%. 
     
     
         20 . The stainless steel according to  claim 17 , further comprising a rare earth element. 
     
     
         21 . The stainless steel according to  claim 13 , comprising austenitic stainless steel. 
     
     
         22 . The stainless steel according to  claim 13 , wherein the stainless steel has no pitting at <1000 mV in an acidic or a neutral environment. 
     
     
         23 . A stainless steel comprising in percentage by weight, 15%<Cr<22%, 13%<Mn<23%, 12%<Ni<23%, and 0.5%<Si<4%, wherein Si can be replaced with an equal amount of Al, Ti and/or V, and wherein the stainless steel has a bilayer passive film structure comprising an inner layer comprising an oxide of a first element, and an outer layer comprising an oxide of a second element, wherein the passivation potential of the first element is lower than the passivation potential of the second element, and the passivation potential of the second element is lower than the transpassivation potential of the first element. 
     
     
         24 . A method of treating a substrate, comprising forming the bilayer passive film structure according to  claim 1  on the substrate. 
     
     
         25 . The method according to  claim 24 , comprising allowing the surface of the substrate to undergo an oxidation reaction. 
     
     
         26 . A water electrolysis anode substrate material, comprising the bilayer passive film structure according to  claim 1 . 
     
     
         27 . An oxygen evolution catalyst, comprising the bilayer passive film structure according to  claim 1 . 
     
     
         28 . A catalyst support, comprising the bilayer passive film structure according to  claim 1 . 
     
     
         29 . A water electrolysis anode substrate material, comprising a bilayer passive film structure formed by the method according to  claim 10 . 
     
     
         30 . A water electrolysis anode substrate material, comprising the stainless steel according to  claim 13 . 
     
     
         31 . An oxygen evolution catalyst, comprising, a bilayer passive film structure formed by the method according to  claim 10 . 
     
     
         32 . An oxygen evolution catalyst, comprising the stainless steel according to  claim 13 . 
     
     
         33 . A catalyst support, a bilayer passive film structure formed by the method according to  claim 10 . 
     
     
         34 . A catalyst support, comprising the stainless steel according to  claim 13 .

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